The Uniswap Universal Router calldata decoder listed V4_SWAP (0x10) in
command names but never decoded its inner actions to extract token
addresses. This caused all V4 swaps (e.g. USDT→USDC) to display as
'Swap ETH → ETH' because tokenIn/tokenOut defaulted to null, which
tokenInfo() resolved as native ETH.
Added decodeV4Swap() which parses the V4 inner action bytes:
- SETTLE (0x0b) → extracts input token currency address
- TAKE (0x0e) → extracts output token currency address
- SWAP_EXACT_IN/OUT and their SINGLE variants → extracts tokens from
pool keys and paths, plus amounts
These addresses are then resolved against the known token list
(TOKEN_BY_ADDRESS) to display correct symbols like USDT, USDC, etc.
Fixes#59
Replace stub error handlers with full approval flow for personal_sign,
eth_sign, eth_signTypedData_v4, and eth_signTypedData. Uses toolbar
popup only (no fallback window) and keeps sign approvals pending across
popup close/reopen cycles so the user can respond via the toolbar icon.
